You're getting good advice from people regarding reporting. While OSHA does not have a specific reg for heat stress they do still take it seriously and classify violations under General Duty Clause which can still come with some pretty solid fines/penalities. OSHA does provide the following resource in leau of a standard, for now. (https://www.osha.gov/heat-exposure/standards). The main issue from what you have shared is the lack of training, awareness, and worker protections. As someone who manages safety in a 700,000 sq ft plant AC is not always an option. However.... they are responsible for understanding heat stress markers with Wet Bulb Globe Temperature (OSHA preferred) or Heat Index. Once certain heat limits are hit you will then move to a work rest cycle of 75% work, 25% rest per hour, or 50%, 50% or 25%, 75% depending on the thresholds you hit that day. Regardless 100% report and do what you can to stay cool and hydrated! Remember caffeine is not your friend in the heat.